Toughness Deterioration of 13Cr-3.8Ni Cast Steel in the Process of Tempering

Abstract

In order to explain the toughness degradation of 13Cr-3.8Ni cast steel due to tempering, a systematic study on the effect of heating temperature and subsequent cooling on mechanical properties has been, carried out. When as quenched martensite is tempered, toughness reaches a minimum at about 550°C and increases with increasing temperature, and then decreases above 650°C as the result of thermal deformation of austenite reverted into martensite during cooling from tempering temperature. The low toughness at about 550°C seems to be due to temper embrittlement. In addition, it is observed that the toughness is deteriorated with the increase of strength when the specimen is cooled at slow rates after tempering.